Two new species and a new genus of ray spiders (Araneae, Theridiosomatidae) from the Ryukyu Islands, southwest Japan, with notes on their natural history Author Suzuki, Yuya https://orcid.org/0000-0001-6523-9272 The United Graduate School of Agricultural Sciences, Kagoshima University, 1 - 21 - 24, Korimoto, Kagoshima-shi, Kagoshima, 890 - 0065, Japan & Graduate School of Systems Life Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819 - 0395 Japan sasaganiya1206@gmail.com Author Hiramatsu, Takehisa Fregrance-Uwado 203, Uwado, Kawagoe-shi, Saitama, 350 - 0816, Japan Author Tatsuta, Haruki https://orcid.org/0000-0001-8847-8874 Graduate School of Systems Life Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819 - 0395 Japan text ZooKeys 2022 2022-07-01 1109 67 101 http://dx.doi.org/10.3897/zookeys.1109.83807 journal article http://dx.doi.org/10.3897/zookeys.1109.83807 1313-2970-1109-67 9C8BF86D194A46EF9D49072D09BF9E48 534F47F344D858A49331F110D3D21111 Theridiosoma dissimulatum Suzuki, Serita & Hiramatsu, 2020 Figs 11 , 12A , 15B Theridiosoma dissimulatum Suzuki, Serita & Hiramatsu, 2020: 137, figs 1E-H, 3D-F, 5C, D, 8A-J, 9A-P, 13E-H (holotype male and paratypes from Amami Island, Japan; not examined). Material examined. Japan , Amami Is. ( Kagoshima Prefecture ) : 1 ♀ , Amami City , Nase-uragami Town ( 28°23'55.6"N , 129°32'27.5"E , alt. 139 m ), 1 Jul. 2021 , Y. Suzuki leg. ; 4 ♀ , Amami City , Sumiyo Town , Nishinakama , Santaro-toge Pass ( 28°15'48.7"N , 129°25'09.0"E , alt. 141 m ), 6 May 2021 , Y. Suzuki leg. ; 1 ♀ , Oshima District , Yamato Village , Oganeku , Materiya-no-taki Waterfall ( 28°19'04.4"N , 129°21'08.2"E , alt. 176 m ), 4 Jul. 2021 , Y. Suzuki leg. Okinoerabu Is. ( Kagoshima Prefecture ) : 2 ♂ 4 ♀ , Oshima District , China Town , Tokudoki ( 27°21'34.5"N , 128°33'02.8"E , alt. 134 m ), 8 Dec. 2021 , Y. Suzuki leg. Okinawa Is. ( Okinawa Prefecture ) : 2 ♂ 3 ♀ , Naha City , Shuri-sueyoshi Town , Sueyoshi-koen Park ( 26°13'39.6"N , 127°42'55.3"E , alt. 25 m ), 7 Mar. 2021 , Y. Suzuki leg. ; 2 ♀ , Kunigami District , Ogimi Village , Nerome ( 26°40'49.7"N , 128°08'01.1"E , alt. 128 m ), 14 Apr. 2021 , Y. Suzuki leg. ; 1 ♀ , Kunigami District , Ogimi Village , Ogimi ( 26°40'57.9"N , 128°08'21.6"E , alt. 311 m ), 15 May 2021 , Y. Suzuki leg. Iriomote Is. ( Okinawa Prefecture ) : 1 ♂ 3 ♀ , Yaeyama District , Taketomi Town , Haiminaka , Otomi-rindo Path ( 24°17'52.6"N , 123°52'47.3"E , alt. 18 m ), 30 Apr. 2021 , Y. Suzuki leg. ; 1 ♂ 3 ♀ , Otomi-daiichi-do Cave ( 24°17'31.0"N , 123°52'45.7"E , alt. 30 m ), 1 May 2021 , Y. Suzuki leg. Remarks. This species can easily be distinguished from T. nigrivirgatum sp. nov. by the presence of a conductor projection on the male palp and a heart-shaped invagination with a pair of spurs on the posterior margin of the female epigynal plate ( Suzuki et al. 2020 ). Refer to the description in Suzuki et al. (2020) for further morphological information. Distribution. Japan (Amami, Okinoerabu, Okinawa, Ishigaki, and Iriomote Islands; Fig. 11 ). Habitat. This species was collected from dim moist forests, especially from locations beside streams (Fig. 12A ). Web morphology. Theridiosoma dissimulatum weaves a concave orb web and drags a tension line with the forelegs. Egg sac. pale reddish brown and spherical with a long horizontal line and a short stalk (Fig. 15B ).